Related Experiment Video
Updated: Jun 6, 2026
08:47
Live Images of GLUT4 Protein Trafficking in Mouse Primary Hypothalamic Neurons Using Deconvolution Microscopy
Published on: December 7, 2017
O-GlcNAc modification, insulin signaling and diabetic complications
1CNRS (UMR 8104), université Paris Descartes, institut Cochin, 22 rue Méchain, Paris, France. tarik.issad@inserm.fr
Diabetes & Metabolism
|November 16, 2010
Summary
O-linked N-acetylglucosamine glycosylation (O-GlcNAcylation) is a glucose-dependent modification regulating protein function. It plays a role in diabetes and Alzheimer's disease by influencing cellular signaling pathways.
Area of Science:
- Biochemistry
- Cell Biology
- Molecular Biology
Background:
- O-linked N-acetylglucosamine glycosylation (O-GlcNAcylation) is a dynamic post-translational modification of serine and threonine residues in cytosolic and nuclear proteins.
- This modification is analogous to phosphorylation, regulating protein stability, activity, and localization, and is sensitive to cellular glucose availability, linking cellular processes to nutritional status.
Purpose of the Study:
- To elucidate the role of O-GlcNAcylation in cellular signaling and its implications in human pathologies.
- To understand how O-GlcNAcylation, regulated by OGT and O-GlcNAcase, functions as a rheostat modulating signal intensity based on nutrient availability.
Main Methods:
- The abstract does not specify experimental methods.
- Focuses on the regulatory role of O-GlcNAcylation by OGT and O-GlcNAcase.
- Discusses the impact of O-GlcNAcylation on signaling pathways like PI-3 kinase.
Main Results:
- O-GlcNAcylation attenuates insulin signaling via the PI-3 kinase pathway, potentially exacerbated by chronic high glucose, contributing to insulin resistance in diabetes.
- O-GlcNAcylation contributes to glucotoxicity, liver glucose overproduction, and pancreatic beta-cell dysfunction.
- O-GlcNAcylation is implicated in diabetic complications, including micro- and macrovascular issues via eNOS modification and promoting profibrotic factors.
Conclusions:
- O-GlcNAcylation acts as a nutritional sensor, influencing cellular signaling and protein function.
- Dysregulation of O-GlcNAcylation is implicated in the pathogenesis of type-2 diabetes and its complications.
- Further research into O-GlcNAcylation could reveal therapeutic targets for metabolic and neurodegenerative diseases.
Related Concept Videos
01:28Insulin: The Receptor and Signaling Pathways
Insulin action is mediated through a receptor tyrosine kinase, akin to the IGF-1 receptor. The number of receptors per cell varies significantly, from 40 on erythrocytes to 300,000 on adipocytes and hepatocytes. The insulin receptor consists of linked α/β subunit dimers, forming a heterotetramer glycoprotein with two extracellular α subunits and two β subunits spanning the membrane. The α subunits inhibit the inherent tyrosine kinase activity of the β subunits, but this inhibition is released...
01:24Type II Diabetes II: Pathophysiology
PathophysiologyType 2 diabetes mellitus (T2DM ) is a chronic metabolic disorder characterized by insulin resistance and progressive pancreatic β-cell dysfunction, leading to impaired glucose homeostasis. It results from interactions among genetic predisposition, environmental factors, and metabolic stressors, such as overnutrition and a sedentary lifestyle.Insulin Resistance and Glucose DysregulationEarly T2DM involves insulin resistance in skeletal muscle, adipose tissue, and the liver.
01:24Glucagon-like Receptor Agonists
Incretins include glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), which stimulate insulin secretion post-meals. In type 2 diabetes, GIP's efficacy is reduced, making GLP-1 a viable drug target. GIP originates from preproGIP.
GLP-1, when administered in high doses intravenously, triggers insulin secretion, inhibits glucagon release, slows gastric emptying, reduces food intake, and restores normal insulin secretion. However, its rapid inactivation by the...
GLP-1, when administered in high doses intravenously, triggers insulin secretion, inhibits glucagon release, slows gastric emptying, reduces food intake, and restores normal insulin secretion. However, its rapid inactivation by the...
01:27Glucose Homeostasis: Pancreatic Islets and Insulin Secretion
The pancreatic islets comprising only 1%-2% of the volume are highly vascularized and innervated mini-organs. They contain five endocrine cell types, including β cells that secrete insulin, which is synthesized as a single polypeptide chain, preproinsulin, processed to proinsulin, and finally to insulin and C-peptide. This process is complex and regulated, involving the Golgi complex, the endoplasmic reticulum, and the secretory granules of the β cell.
Insulin and C-peptide are co-secreted in...
Insulin and C-peptide are co-secreted in...
01:16Hormones Regulating Blood Glucose
Insulin is released by beta cells of the pancreas when blood glucose levels are high. It facilitates glucose absorption and utilization in insulin-dependent cells with insulin receptors on their plasma membranes. Insulin promotes glucose uptake by increasing the number of glucose transport proteins in the cell membrane, allowing glucose to enter the cell. As a result, glucose utilization and ATP production are enhanced.
In addition to accelerating glucose uptake and utilization, insulin has...
In addition to accelerating glucose uptake and utilization, insulin has...
01:25Insulin: Biosynthesis, Chemistry, and Preparation
The endoplasmic reticulum (ER) of pancreatic β-cells synthesizes preproinsulin, which consists of a signal peptide, A and B chains, and a C-peptide. Preproinsulin is then cleaved and folded into proinsulin, which translocates to the Golgi apparatus for sorting and packaging into secretory granules. In these granules, enzymatic clipping generates insulin and C-peptide.
Damage or functional impairment of β-cells inhibits insulin production, leading to diabetes. Diabetes treatment primarily uses...
Damage or functional impairment of β-cells inhibits insulin production, leading to diabetes. Diabetes treatment primarily uses...